Projectile and cartridge arrangement

ABSTRACT

A projectile having a guard ring of circumferentially spaced posts encompassing a convex nose rupture disc and web. The projectile is mounted in a case with the nose extending in exposed condition beyond the open case end. A dual diameter chamber high-low propellant firing and gas expansion arrangement is utilized in the cartridge in conjunction with the reduced diameter tapered and finned rear end of the projectile.

United States Patent 11 1 Abbott 1 51 Dec. 4, 1973 PROJECTILE ANI) CARTRIDGE ARRANGEMENT Jungermann et al. 102/91 3,170,405 2 1965 3,429,263 2 1969 Snyder et a1 102 92.7 3,528,662 9/ 1970 Merchant et al. 102/66 X 3,245,348 4/1966 Lahr 102 38 3,181,465 5 1965 Anthony. 102 41 1,188,178 1916 Isham 102/53 3,557,702 1 1971 Benson 102 92.7

FOREIGN PATENTS OR APPLICATIONS 530,433 7/1954 Belgium 102 53 [52] US. Cl. 102/41, 102/43 C, 102/43 P, Primary Examiner Robert R Stahl I I 102/44 102/53 102/92 102/ Attorney-Reginald F. Pippin Jr.

[51] Int. Cl..... F42b 11/18, F42b 11/36 [58] Field of Search 102/49.2, 53, 49.1, [57] ABSTRACT 92 6 38 91 A pro ectile havlng a guard ring of c1rcumferent1ally spaced posts encompassing a convex nose rupture disc [561 fi'ieli i fii i'fi iigiiii iiifi n ififi ti l igzfi UNITED STATES PATENTS case end. A dual diameter chamber high-low propel- Austin, Jr. and gas expansion arrangement is utilized in 2 (E/ 3 4 the cartridge in conjunction with the reduced diameames e 1,384,841 7 1921 Lundell 102/53 tapered and finned rear 7 the pmlect'le 3,156,187 1l/1964 Batou 102/41 23 Claims, 7 Drawing Figures 3Q776Ll37 ,PMENTEDUEI: 4 ms DAVID D. ABBOTT INVENTOR PROJECTIIJE ANDv CARTRIDGE- ARRANGEMENT This invention relates to an improvedcartridge and projectile arrangement which is of tparticular value; in

enabling the. handling, firing and effective-target impactin'g-ofprojectiles which may; desirably carry;.a flowe able. chargeof material, and particularly aliquidtagent; Variousaspects of the inventionarealsousefultin enablinggthe: improved firing of other projectiles:

Projectiles havebeert employed whichwcarry: liquid a agents: for'dissemina tion' at'a target. lnvone; s' uch' arrangement, a-projecti'lc is provided'wh'icli' is afrangible. andisfired from acartridge case,- the'projectiletbeing protected '=ataits forward endiby. enclosurevwithin the.

forward openend of the case: whilea'thisiswa.satisfac tory arrangement forsome weapons, panticularlydhose. which" employ. relatively small; cartridges: and." which. have sufficient'room in the cartridgeeireceiving-; rchambet to enable the projectile to be..satisfactorilyvfired-: from within the case and-"to effectivelyy-ride rdowrr:the:

bore: of the barrel; this nose-encompassing arrangee mentisnot practical in all circumstances, andl-particue lady inthe larger gaugesrounds, suclr'as in'2rounds;-for existinglarge-caliber hand held"gas guns: (e.g;.-, 37- and 3 8 millimeter) and 40-millimeter:grenadelauncherst: In 1 such cases it is desirable that-the bore ridi'ng section of. the projectile closely approximate. the. outside diameter offthe cartridge case, in order to accommodateathevariousdiametral: conditions of barrel Fbore :andicartridge+ receiving chamber in which these rounds-maybe fired; However, if the projectile extends beyond the cartridge. case and is made frangible. in its-nosearea; it :will be ap paren-t'that the cartridge will be subjectzto undesirable breakage during handling, as particularljnwhen thecartridge. is inadvertently dropped ontoahardisurface. It. is accordingly a feature of th'einvention:to -provideiai cartridge and projectile arrangement t and at projectile. which will enable the projectile. to:be; adequately;protected when such is exposed and dropped:

' It is a further object of the inventioneto provider-an improved projectile arrangement which not only af fords improved drop protection for its rupturablenose section butwhich alsois ofadvantage'in-affording de sirable rupture characteristics on contact with va target, includinghard'targets 'struck'flat on or. at anangle, as

well as the ground or othersoftertargetxstruckzflat on or'at'an angle. I

It'is-a further object of the inventionto provide. aprojectile arrangement which affordsarelativelyflafitrajectory with limited range; and 'whichztherebyenables its use under more controlled conditions inr'circurnstances where extended range is not desirable, such aspolice work. Still a 'further'object of another aspect' ofthe invention is 1 the provision of 'a cartridge 1 and Z projectile arrangei'n'ent utilizing a'high-low'dualichambe'r propellant: firing and gas expansion system in conjunetioncwith an appropriately reduced rear end "diameter projectile: so. as-to 'afford' adequate combustion of 1 the propellantiand adequate. protection -of the rear end iof' thezprojectile :as may be required; while enablingthe utilization of sime ple and inexpensive construction .andparts.

- Still other objects, features and gattendantadVantages will-become apparent to one skilled-initheartfroma:

reading of. the following-detaileddescriptions agre ferredrembodimentaof the invention; :taken in tconjunc; 1 tion with the following drawings, .wherein:

FIG. l is a. perspective view of a cartridge according to the invention.

FIG. 2 is a perspective view F163 is an end view of the projectile of FIG. 2.

FIG. 4'is a longitudinal section view of the cartridge of FIG. 1;

FIG. 5 is a perspective view, partly broken away, of

-a .wad employed in the cartridge of FIG. 4.-

FIG. 6 is a fragmentarylongitudinalsection: view dia gramatically illustratingthe operation of'th'e wad during firing of the propellant in the. cartridge. of FIG. 5. FIG. 7.is a fragmentary longitudinal. section view of "amodification .of the cartridge, case. arrangement ac- Projectile 31has a bore-riding. section 41 which is cylindrical .in external shape, and a hose 51 which has a circumferential forwardly extending guard ring generally indicated atfl 1', forrned'by a plurality of spaced guard posts 73 which extend forwardly of their base connections with the remaining portion of the nose. The noseS'l. also, has a rupture disc 61 surrounded by an annular ruptureweb 67 formed by reducing the thickness of the nose as bythe employment of an annulargroove 65, as indicated in FIG. 4. The rupture web is disposed inboard of the base of the guard ring posts 73.; thereby enabling the rupture disc 61 to be ruptured either forwardly or rearwardly relative to the posts 73. The forward end of the projectile nose 51 is formed by the frontal-surface 6310f the rupture disc 61, which frontal surface is convex, and of a forward extent corresponding tothe forward extent of the posts 73, although the. forwardmos't face 63a may extend slightly forwardly of the posts within the impact yield limits of the nose material, and may extend rearlwardly of the,

posts as may bedesired. The guard rin g 71 formedby posts'73zthus serves to provide a substantial measure of protection tothe rupture disc 61 due to inadvertent dropping of the cartridge 11 or projectile 31 on its nose and, while enabling the rupture disc 6l'to be ruptured on projectile impact at high velocities may be en countered-when the projectile is tired in the normal manner from the cartridge case 21,

The guard ring 7 l= isexte,mally inw ardly tapered in the forward-direction, including the convex externalsurfaces of-the posts 73, as well as the external surface ofthe base'portion therefor forward of the bore-riding section .41 of the projectile. This isadvantageous in af fording not only good mold releaseof this part, but also in :aiding in loading of the cartridgein a chamber and' in providing a degree of streamlining of the nose 51,.

while still-affording a desirable degree of projectile retardation and limiting'of flight range. In addition, the tapering of the posts 73tends to aid in penetration of some targets, thereby affording better barricade peneration and dissemination of: the material F within the projectile upon impact and rupture of .the nosesection of a projectile according to the invention and contained inthe-cartridgeoflFlG.

and other portions of the projectile body. The posts 73 are also preferably outwardly tapered on their internal surfaces 73b, and this also aids in target penetration, as well as affording better mold release of the part and more free forward rupture motion for the rupture disc 61 in those instances where forward motion of the rupture disc may take place on target impact, such as for instance when the target is impacted at an angle and the momentum of the fill material F in the projectile tends to effect a forward rupture of the disc 61. The rupture disc 61 may take various shapes and configurations, as may the rupture web 67 associated therein, a preferred embodiment being as shown with a concaveshaped internal surface and a convex-shaped external surface 63, 63a.

The nose 51 is formed separately from the rear section of the projectile, including the bore-riding section 41 and a tapered rear section 33 having fins 35 thereon. The projectile has a filling of flowable material F, which may preferably be a partial charge of highly volatile liquid agent which will form minute particles upon impact release from the projectile 31. An air space is desirable within the projectile, to accommodate thermal expansion of the liquid F and the vapor pressure therefrom. or such other flowable or otherwise disseminable material F as may requite such expansion space, such as some powdered materials having a high coefficient of thermal expansion. The entire projectile 31 is preferably formed of frangible relatively rigid plastic material, which has sufficient strength to withstand the launch pressures encountered when the cartridge is fired, and which is sufficiently chemically inert to the fill material F to afford adequate storage life. In addition, it is desirable that the material of the projectile 31 be capable of adequate bonding to afford a hermetic sealed condition for the fluid or other agent F therein, it being preferable that the plastic material be capable of welding, as by spin-welding or ultrasonic techniques. A suitable construction for spin-welding is afforded by the complementary stepped shoulders 39 and 55 on the nose and rear sections of the projectile respectively. If desired, other suitable joint or sealing connections may be employed for a particular embodiment.

Particular plastics which may be suitable for construction of the entire projectile 31, utilizing conventional injection molding techniques, are glass-filled nylon, (e.g., 30 percent glass-filled Type 6/ 6 nylon), and acetal resin(e.g., such as marketed underthe trademarks Delrin and Celcon). In addition, it is feasible to form the projectile or portions thereof from other materials, such as tempered glass or metal (e.g, zinc, aluminum, lead alloys, etc.) of suitable strengthcharacteristics to accommodate the forces and pressures encountered and as may be readily calculated for a given construction and conditions of anticipated use.

As noted above, the rear section of the projectile rearward of the annular bore-riding section 41 is tapered as indicated at 33, and has tapered fins 35 extending from its surface, the fins 35 being preferably canted to afford spin stabilization, and also to afford a rotational motion to the projectile 31, including its fill meten'al F, which may aid in dissemination of the fill material at impact through the action of the angular momentum of the fill material.

The projectile 31 is retained in the cartridge case 21 through the medium of a snap-ring lip and groove connection formed by an annular internally protruding lip Wall 25 may be formed of suitable thickness-to pro- 1 vide the necessary cohesive strength towithstand the stresses encountered during firing of the cartridge within a given cartridge-receiving chamber in a weapon, it being understood .that some weaponcartridge-receiving chambers are slightly oversize and require sufficient strength, ductility and/or elasticity to enable the case to expand, while other cartridgereceiving chambers are more close-fitting and require less strength, ductility and/or elasticity for the cartridge case.

It is desirable that the cartridge case be formed of a sufficiently tough and ductile material to enable the satisfactory release of the projectile from the case upon firing of the cartridge. In the particular illustrative embodiment as illustrated, suitable injection moldable materials for the case 21 include thermoplastic resins such as polycarbonate, polyethylene, polyurethane, polypropylene and impact-grade polystyrene. In addition, the case may be formed of other materials, such as metal, including brass, aluminum, steel, etc., as well as tougher impact-grade rubber formulations and other elastomers of adequate strength and ductility.

The external shape of the cartridge case 21 may be formed as may be required to enable placement in a given cartridge-receiving chamber for firing, and may include a stepped enlarged rear section anda conventional rim at the base section 23 thereof, or may have other external configurations as may be appropriate for a given desired utilization. v

Disposed within the base 23 of the cartridge case 21 is a percussion primer 91 which enables the ignition firing of a suitable propellant mix 93 which is enclosed within a reduced diameter bore 92, with a borerestricting wad 81 across the entrance of the reduced diameter bore 92 and effectively forming a restricted volume chamber for initial holding of the propellant charge 93 and for subsequent restriction and timedelayed release of the propellant and propellant gases during firing, as will be more particularly described.

.While various propellant formulations may be employed, a suitable propellant formulationjhas been afforded by propellant marketed under the namejof WC Blank, a particular quantity of approximately one gram having been sufficient to afford adequate firing and launching of aproje'ctile of approximately 67 grams 7 weight and an outer diameter of approximately 37 millimeters at the bore-riding diameter formed by the section 41. f

The wad 81 in the illustrative and preferred embodiment of FIG. 4, takes the form of a cylinder'having an outer ring wall 85, engaging in frictional press fit relation within the'bore 92, and having an obturating lip 85a formed thereon in'interfacing relation to .the propellant powder charge 93. A collapsible folding lateral wall 89 extends between a central stem or post 83 and the outer ring wall 85, with radial reinforcing webs 87. The central stem or post 83 may have an airial bore 83a formed therein to aid in insertion of the vxjad 81 within the bore 92, allowing air to escape during insertion, and

a chamfer 92a may be formed on the forward edge of the bore 92 to likewise aid in insertion of the wad 81 within the bore 92. It is desirable that the granule size of the propellant mix 93 be sufficient to prevent exit of any material quantity thereof throughthe axialbore 83a, or that the bore otherwise be effectively closed'by the contact and with the protruding rear-end 37 of'the projectile 31. By making the hole -83a,very minute, or otherwise by sacrificing the air equalization characteristic as by elimination of the bore 83a, the small *cross sectional rearmost end 31- of the projectile may. be slightly spaced from the central stem or post'83 ifs .desired, or as may be encountered in .the course of-manuacture on a production basis. The. wad,8.lmay be formed of various materials-whichmay-beydeformable under pressure, including various thermoplastic resins.

such as nylon, polyethylene, etc. The material is also preferably frangible in shear, as is:a;fforded-by these thermoplastic materials.

In firing the cartridge to propelthe projectile 31. therefrom, the primer 91 is percussivelyfiredas by.aconventional firing pin (not shown) to thereby ignite the propellant mix 93, as schematically indicated in FIG. 6, this ignition of the propellant'mix creating gases which increase the gas pressure within the chamber encompas'sing the burning propellant mix. This gaspress ward under this gas pressure and is deformed and/or sheared by its contact with the rear end ofathesubstantially stronger fins 35 on the projectile, 31; Thewad 81 may ultimately be deformed to the pointzofeomplete. segmenting into smaller sheared sectionsbyitscontact with the fins 35, although this may not occurzin, all instances, particularly where a smaller effective charge of propellant is utilized for a given projectile massper unit aa condition. In any event, as shown in FIG. 6, theretention of the projectile within the case :21, as well asthe inertia of the projectile mass, serves'in conjunction with the interfacing contact made between the. small:

reduced diameter rear 37 of the projectile and the wad 81 to retain the wad in the reduced diameter=bore 92" over a period of time to aid inaffordingadequate. bume ing of the propellant 93, thereby enablingthedesirable.

utilization of a propellant which requires'higher'than atmospheric pressure for effectiveburningfilhe wad 81- will ultimately be moved in deformed%condition--into. the chamber void area formed by therenlarged bore section of the case wall 25 surrounding the fihs'35 the tapered reduced diameter rear; section-33 ofth'e projectile '31, thereby enabling the full application of a reduced propellant gas pressureto the-"extemal rear body section of the projectile. Atsome. point during this-propellant firing and gas expansion cycle, the for wardly exerted forceyon the projectileflllwillibe. suffi-.

cient to overcome the restraining force thereon by the, snap, ring connection 27, 33a between: thecaseand the projectile 31 aswell as the inertial force. of the projec-. tile and fill material therein. A desirablemode'of open ation is afforded when the case/projectile retention and projectile inertial forces are overcome: after completevv expulsion of thewad. 81 from the reduced diameter bore 92, although this precise timinggis not critical, as:

adegree of forward motion of the projectile may be initiated by the directforces exerted onits rear end 37 through wad'fstem 83,,while the wad is in process of its short term time-delayed volume restricting and release action relative to the propella'nt chamber bore92. It will be noted in this respect. that the reduced diameter end 37 of the projectile enables this deformed expulsion of the wad 81, without requiring that the projectile be moved forward to enable this expulsion. It will be appreciated that this overall dual diameter bore, wad, and reduced diameter 'projectile arrangement affords a unique and advantageous high-low propellant firing arrangement which affords adequate propellant buming while providing for reduced pressures on the external exposed rear surface of the projectile, andlthereby enablingthe projectile body to beof lesser strength than would otherwise be required if the full burning pressure forand burning action'of the propellant were exerted directly on the hollow-wall portion of the projectile.

The deformable and frangible wad or wadding 81 may take other'forms within this aspect of the invention, a modifications being illustrated in FIG. 7 in which the wad 181 takes the form of a disc of cork, preferably a composition of particulate cork adhesively bonded into a common substantially disintegrable mass which may have frangible sheets of paper or the like on its front and rear surfaces for ease of handling and prefiring self-integrity of shape and form. Cork wadding of this type is commercially available'under the name Sacork, and the thickness may bevaried to obtain a desired degree of gas-pressure retention capability before break up and/or crushing sufficient to afford pressure release of the propellant gases into the expansion chamber formed by the nlarged bore of case wall 25. While the invention :has been described with respect to illustrative physical embodiments in accordance with various aspects thereof, it will be apparent that various modifications and improvements may be made without departing. from the scope of the invention. Accordingly it is to be understood that the invention is not to be limited by the illustrative physical'embodiments but only by the scope of the appended claims.

I claim: 1. A cartridge comprising a case open at one end, a projectile disposed in said case and. having a portion thereof protruding through and beyond said open end of said casing, v v v said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly beyond the forward end of "said central ,frontal zone to protect said. central frontal zone, said guard ring comprising plurality of circumferentially disposedforwardly extending protrusions with, individually .freeforward ends. 1 2. Acartridge according to' claim 1, said forwardly extending protrusions forming discrete cantilever form posts with free protruding,

ends. v g 3. A cartridge accordingto claim 2,5 said discrete cantilever form postsbeingcircumferen'tially spaced apart at their forward ends. 4. A cartridge according to claim 3, l the extema]. surface ofsaid discrete posts being'forwardly inwardly tapered. 5. Acartridge according to claim 4,

the internal surfaces of said discrete posts disconnected at their forward ends being forwardly outwardly tapered.

6. A cartridge according to claim 5,

said external and internal surfaces being respectively convex and concave in frontal view.

7. A cartridge comprising a case open at one end,

a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing,

said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly to protect said central frontal zone,

said central frontal zone being outwardly convex and said guard ring extending forward about said convex central frontal zone,

said guard ring comprising a plurality of circumferentially disposed forwardly extending protrusions,

said forwardlyi extending protrusions forming discrete posts,

said discrete posts being circumferentially spaced apart,

said projectile having a cavity containing a charge of flowable material,

said central frontal zone including a weakened rupture zone for enabling rupture of said central frontal zone and release of said charge of flowable material therethrough when said projectile strikes a target at a sufficient velocity to effect rupture of said weakened zone and/or one or more of said posts while said posts enable an effective measure of protection of said central frontal zone at lower velocity inadvertent handling impacts.

8. A cartridge comprising a case open at one end,

a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing,

said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly to protect said central frontal zone,

said central frontal zone being outwardly convex and said guard ring extending forward about said convex central frontal zone,

said projectile having a cavity containing a charge of flowable material,

said central frontal zone including a weakened rupture zone for enabling rupture of said central frontal zone and release of said charge of flowable material therethrough when said projectile strikes a target at a sufficient velocity to effect rupture of said weakened zone and/or said guard ring, while said guard ring enables an effective measure of protection of said central frontal zone at lower velocity inadvertent handling impacts.

9. A cartridge according to claim 8,

said case and projectile having a snap-ring and groove connection therebetween at the forward central section of said projectile forward of said tapered rear section and at the forward open end of said case,

and said projectile having a bore-riding section extending beyond said snap-ring and groove connection and being of a diametergreater than the interior of said case open end to enable such to snugly fit in a barrel bore of diameter closely complementary to the diameter of said case.

10. A cartridge according to claim 8,

and said projectile having a bore-riding section extending beyond said snap-ring and groove connection and being of a diameter greater than the interior of said case open end to enable such to snugly fit in a barrel bore of diameter closely complementary to the diameter of said case.

11. A cartridge comprising a case open at one end,

a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing,

said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly to protect said central frontal zone, I

said projectile having a cavity containing a charge of flowable material,

said central frontal zone including a weakened rupture zone for enabling rupture of said central frontal zone and release of said charge of flowable material therethrough when said projectile strikes a target at a sufficient velocity to effect rupture of said weakened zone and/or said guard ring, while said guard ring enables an effective measure of protection of said central frontal zone atlower velocity inadvertent handling impacts.

12. A cartridge according to claim 11,

said projectile being formed of relatively rigid frangible cured resin and said charge of flowable material being a volatile liquid agent,

said projectile having a tapered rear section with stabilizing fins thereon.

13. A cartridge according to claim 12,

said open end of said case being formed of a tough impact grade resin.

14. A cartridge according to claim 12,

said projectile resin being glass-filled nylon.

15. A cartridge according to claim 12,

said projectile resin being acetal resin.

16. A cartridge according to claim 12,

said case and projectile having a snap-ring and groove connection therebetween at the forward central section of said projectile forward of said tapered rear section and at the forward open end of said case,

and said projectile having a bore-riding section extending beyond said snap-ring and groove connection and being of a diameter greater than the interior of said case open end to enable such to snugly fit in a barrel bore of diameter closely complementary to the diameter of said case.

17. A cartridge comprising a case open at one end,

a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing,

said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly to protect said central frontal zone,

said projectile, having a cavity containing a charge of flowable material,

said central frontal zone including a weakened rupture zone for enabling rupture of said central frontal zone and release of said charge of flowable material therethrough when said projectile strikes a target at a sufficient velocity to effect rupture of said weakened zone and/or one or more of said posts while said posts enable an effective measure of protection of said central frontal zone at lower velocity inadvertent handling impacts,

said case and projectile having a snap-ring and groove connection therebetween at the forward central section of said projectile forward of said tapered rear section and at the forward open end of said case,

and said projectile having a bore-riding section extending beyond said snap-ring and groove connection and being of a diameter greater than the inter.- ior of said case open end to enable such to snugly fit in a barrel bore of diameter closely complementary to the diameter of said case.

18. A cartridge comprising a case open at one end,

a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing,

said protmding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly to protect said central frontal zone,

said projectile having a cavity containing a charge of flowable material,

said central frontal zone including a weakened rupture zone for enabling rupture of said central frontal zone and release of said charge of flowable material therethrough when said projectile strikes a target at a sufficient velocity to effect rupture of said weakened zone and/or one or more of said posts while said posts enable an effective measure of protection of said central frontal zone at lower velocity inadvertent handling impacts,

and said projectile having a bore-riding section extending beyond said snap-ring and groove connection and being of a diameter greater than the interior of said case open end to enable such to snugly fit in a barrel bore of diameter closely complementary to the diameter of said case.

19. A cartridge comprising a case having a projectile therein,

said projectile having a tapered rear section with stabilizing fins thereon,

said-case having a first bore section containing said tapered rear section with stabilizing fins thereon,

said case having a second bore section rearwardly of and smaller in diameter than said first bore section,

a charge of ignitable propellant powder in said second bore section,

and a frangible bore-restricting wad disposed in said second bore section and between said charge of propellant powder and the tapered finned rear end of said projectile,

said tapered rearmost end of said projectile being smaller in its rear end cross section than said second bore section and being disposed closely adjacent the effective forward surface of said wad.

20. A cartridge according to claim 19,

said fins extending outwardly from said tapered rear section and across the forward end of said second bore in the zone forward of said wad.

21. A cartridge according to claim 19,

said first bore section having voids therewithin in the zones between said fins and the exterior of said tapered rear section.

22. A cartridge comprising a case having a projectile therein,

said projectile having a forward section and a reduced diameter rear end, I

said casehaving a first bore section containing said reduced diameter section and at least a portion of the larger section forward thereof,

said case having a second bore section rearwardly of and smaller in diameter than said first bore section,

a charge .of ignitable propellant powder in said second bore section,

and a bore-restricting frangible blow-out wad removably disposed in said second bore section and between said charge of propellant powder and the reduced diameter rear end of said projectile,

said reduced diameter rear end of said projectile being smaller in its rear end cross section than said second bore section and wad and being disposed closely adjacent the effective forward surface of said wad.

23. A cartridge comprising a case having a projectile therein,

said projectile having a forward section and a reduced diameter rear end,

said case having a first bore section containing said reduced diameter section and at least a portion of the larger section forward thereof,

said case having a second bore section rearwardly of and smaller in diameter than said first bore section,

a charge of ignitable propellant-powder in said second bore section, I

and a bore-restricting frangible blow-out wad removably disposed in said second bore section and between said charge of propellant powder and the reduced diameter rearend of said projectile, J

said reduced diameter rear end of said projectile being disposed closely adjacent the effective forward surface of said wad.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,776,137

DATED 1 December 4, 1973 Q I |NVENTOR(S) 2 David D. Abbott It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, Line 27, change "hose" to -nose-,

Column 2, Line 65, change "pener" to -penetr--. Column 3, Line 25, to

Column 3, Line 26, "requite" to -require-,

Column 3, Line 62, "meterial" to --material-- Column 5, Line 14, "nuacture" to -nufacture-,

Column 5, Line 40, change "aa" to --area-.

Column 6, Line 21 "modifications" to --modification-- Column 6, Line 34, change "nlarged" to --enlarged-- Signed and Scaled this Thimmh Day Of .Ianuaryl98l [SEAL] .4 Rest:

SIDNEY A. DIAMOND Arresting Ojficer Commissioner of Patents and Trademarks UNITED STATES PATENT AND TRADEMARK OFFICE PATENT NO. 3,776,137

DATED December 4, 1973 U INVENTOR(S) I David D. Abbott It is certifid that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, Line 27, change "hose" to --nose---, Q n 1 Column 2, Llne 65, change pener' to -penetr---. Column 3, Line 25, to

Column 3, Line 26, "requite" to require-, b Column 3, Line 62, "meterial" to material--.

Column 5, Line 14, "nuacture" to -nufacture--, Column 5, Line 40, change "aa" to area--.

Column 6, Line 21 "modifications" to --modificationb Column 6, Line 34, change "nlarged" to -enlarged- Sigurd and Scaled this Thirteenth Day Of January I981 [SEAL] k Anesr:

SIDNEY A. DIAMOND Arresting ()jficer Commissioner of Patents and Trademarks 

1. A cartridge comprising a case open at one end, a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing, said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly beyond the forward end of said central frontal zone to protect said central frontal zone, said guard ring comprising a plurality of circumferentially disposed forwardly extending protrusions with individually free forward ends.
 2. A cartridge according to claim 1, said forwardly extending protrusions forming discrete cantilever form posts with free protruding ends.
 3. A cartridge according to claim 2, said discrete cantilever form posts being circumferentially spaced apart at their forward ends.
 4. A cartridge according to claim 3, the external surface of said discrete posts being forwardly inwardly tapered.
 5. A cartridge according to claim 4, the internal surfaces of said discrete posts disconnected at their forward ends being forwardly outwardly tapered.
 6. A cartridge according to claim 5, said external and internal surfaces being respectively convex and concave in frontal view.
 7. A cartridge comprising a case open at one end, a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing, said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly to protect said central frontal zone, said central frontal zone being outwardly convex and said guard ring extending forward about said convex central frontal zone, said guard ring comprising a plurality of circumferentially disposed forwardly extending protrusions, said forwardly extending protrusions forming discrete posts, said discrete posts being circumferentially spaced apart, said projectile having a cavity containing a charge of flowable material, said central frontal zone including a weakened rupture zone for enabling rupture of said central frontal zone and release of said charge of flowable material therethrough when said projectile strikes a target at a sufficient velocity to effect rupture of said weakened zone and/or one or more of said posts while said posts enable an effective measure of protection of said central frontal zone at lower velocity inadvertent handling impacts.
 8. A cartridge comprising a case open at one end, a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing, said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly to protect Said central frontal zone, said central frontal zone being outwardly convex and said guard ring extending forward about said convex central frontal zone, said projectile having a cavity containing a charge of flowable material, said central frontal zone including a weakened rupture zone for enabling rupture of said central frontal zone and release of said charge of flowable material therethrough when said projectile strikes a target at a sufficient velocity to effect rupture of said weakened zone and/or said guard ring, while said guard ring enables an effective measure of protection of said central frontal zone at lower velocity inadvertent handling impacts.
 9. A cartridge according to claim 8, said case and projectile having a snap-ring and groove connection therebetween at the forward central section of said projectile forward of said tapered rear section and at the forward open end of said case, and said projectile having a bore-riding section extending beyond said snap-ring and groove connection and being of a diameter greater than the interior of said case open end to enable such to snugly fit in a barrel bore of diameter closely complementary to the diameter of said case.
 10. A cartridge according to claim 8, and said projectile having a bore-riding section extending beyond said snap-ring and groove connection and being of a diameter greater than the interior of said case open end to enable such to snugly fit in a barrel bore of diameter closely complementary to the diameter of said case.
 11. A cartridge comprising a case open at one end, a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing, said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly to protect said central frontal zone, said projectile having a cavity containing a charge of flowable material, said central frontal zone including a weakened rupture zone for enabling rupture of said central frontal zone and release of said charge of flowable material therethrough when said projectile strikes a target at a sufficient velocity to effect rupture of said weakened zone and/or said guard ring, while said guard ring enables an effective measure of protection of said central frontal zone at lower velocity inadvertent handling impacts.
 12. A cartridge according to claim 11, said projectile being formed of relatively rigid frangible cured resin and said charge of flowable material being a volatile liquid agent, said projectile having a tapered rear section with stabilizing fins thereon.
 13. A cartridge according to claim 12, said open end of said case being formed of a tough impact grade resin.
 14. A cartridge according to claim 12, said projectile resin being glass-filled nylon.
 15. A cartridge according to claim 12, said projectile resin being acetal resin.
 16. A cartridge according to claim 12, said case and projectile having a snap-ring and groove connection therebetween at the forward central section of said projectile forward of said tapered rear section and at the forward open end of said case, and said projectile having a bore-riding section extending beyond said snap-ring and groove connection and being of a diameter greater than the interior of said case open end to enable such to snugly fit in a barrel bore of diameter closely complementary to the diameter of said case.
 17. A cartridge comprising a case open at one end, a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing, said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly to protect said central frontal zone, said projectile having a cavity containing a charge of flowable material, said central frontal zone including a weakened rupture zone for enabling rupture of said central frontal zone and release of said charge of flowable material therethrough when said projectile strikes a target at a sufficient velocity to effect rupture of said weakened zone and/or one or more of said posts while said posts enable an effective measure of protection of said central frontal zone at lower velocity inadvertent handling impacts, said case and projectile having a snap-ring and groove connection therebetween at the forward central section of said projectile forward of said tapered rear section and at the forward open end of said case, and said projectile having a bore-riding section extending beyond said snap-ring and groove connection and being of a diameter greater than the interior of said case open end to enable such to snugly fit in a barrel bore of diameter closely complementary to the diameter of said case.
 18. A cartridge comprising a case open at one end, a projectile disposed in said case and having a portion thereof protruding through and beyond said open end of said casing, said protruding portion having a central frontal zone surrounded by a forwardly protruding guard ring extending forwardly to protect said central frontal zone, said projectile having a cavity containing a charge of flowable material, said central frontal zone including a weakened rupture zone for enabling rupture of said central frontal zone and release of said charge of flowable material therethrough when said projectile strikes a target at a sufficient velocity to effect rupture of said weakened zone and/or one or more of said posts while said posts enable an effective measure of protection of said central frontal zone at lower velocity inadvertent handling impacts, and said projectile having a bore-riding section extending beyond said snap-ring and groove connection and being of a diameter greater than the interior of said case open end to enable such to snugly fit in a barrel bore of diameter closely complementary to the diameter of said case.
 19. A cartridge comprising a case having a projectile therein, said projectile having a tapered rear section with stabilizing fins thereon, said case having a first bore section containing said tapered rear section with stabilizing fins thereon, said case having a second bore section rearwardly of and smaller in diameter than said first bore section, a charge of ignitable propellant powder in said second bore section, and a frangible bore-restricting wad disposed in said second bore section and between said charge of propellant powder and the tapered finned rear end of said projectile, said tapered rearmost end of said projectile being smaller in its rear end cross section than said second bore section and being disposed closely adjacent the effective forward surface of said wad.
 20. A cartridge according to claim 19, said fins extending outwardly from said tapered rear section and across the forward end of said second bore in the zone forward of said wad.
 21. A cartridge according to claim 19, said first bore section having voids therewithin in the zones between said fins and the exterior of said tapered rear section.
 22. A cartridge comprising a case having a projectile therein, said projectile having a forward section and a reduced diameter rear end, said case having a first bore section containing said reduced diameter section and at least a portion of the larger section forward thereof, said case having a second bore section rearwardly of and smaller in diameter than said first bore section, a charge of ignitable propellant powder in said second bore section, and a bore-restricting frangible blow-out wad removably disposed in said second bore section and between said charge of propellant powder and the reduced diameter rear end of said projectile, said reduced diameter rear end of said projectile being smaller in its rear end cross section than said second bore section and Wad and being disposed closely adjacent the effective forward surface of said wad.
 23. A cartridge comprising a case having a projectile therein, said projectile having a forward section and a reduced diameter rear end, said case having a first bore section containing said reduced diameter section and at least a portion of the larger section forward thereof, said case having a second bore section rearwardly of and smaller in diameter than said first bore section, a charge of ignitable propellant powder in said second bore section, and a bore-restricting frangible blow-out wad removably disposed in said second bore section and between said charge of propellant powder and the reduced diameter rear end of said projectile, said reduced diameter rear end of said projectile being disposed closely adjacent the effective forward surface of said wad. 